#include <stdio.h>
#include <stdlib.h>

int a[8];
char *day[]
    ={"","MONDAY","TUESDAY","WEDNESDAY","THURSDAY","FRIDAY","SATURDAY","SUNDAY"};

int main()
{
    int i,t,j;
    a[4] = 6;
    for(i = 1;i <=3;i++)
    {
        a[i] = 2;
        if(!a[i+3])
        a[i+3] = 7;
        else
        {
            a[i] = 0;
            continue;
        }
        for(t = 1;t <= 3;t++)
        {
            if(!a[t])
            a[t] = 5;
            else continue;
            if(!a[t+2])
            a[t+2] = 4;
            else
            {
                a[t] = 0;
                continue;
            }
            for(j = 5;j < 7;j++)
            {
                if(!a[j])
                a[j] = 3;
                else continue;
                if(!a[j+1])
                a[j+1] = 1;
                else
                {
                    a[j] = 0;
                    continue;
                }
                for(i = 1;i <= 7;i++)
                printf("Doctor %c is on duty %s.\n",'A'+a[i] - 1,day[i]);
                exit(0);
            }
        }
    }
}